1. Field of the Invention
The present invention relates to a compressor with a built-in electric motor which is suitable to be mounted on a mobile structure such as a motor vehicle. The invention also relates to a mobile structure having such a compressor.
2. Description of Related Art
In a vehicle driven only by an engine, a compressor driven by the engine has been used for air-conditioning the vehicle compartment with the compressor being mounted alongside of the engine.
Hybrid vehicles having both an engine and an electric motor and traveling by use of one of them according to conditions have been practically used for traveling on public roads. Air-conditioning of the vehicle compartment of this hybrid vehicle is made by a compressor driven by the engine in the same manner as conventional engine-driven vehicles, which compressor is mounted alongside of the engine.
It is proposed that the engines of hybrid vehicles should be shut off while they are temporarily stationary at places such as a traffic light in order to reduce effects of the engine upon the environment. When the proposal is followed with a vehicle where a compressor driven by the engine is used, air-conditioning stops each time when the vehicle stops, causing a problem for the driver and passengers in the compartment in summer and winter seasons, and especially in regions with extremely cold or hot climate.
For solving such a problem, there is an idea of adopting a compressor to be driven by an electric motor, especially a compressor to be used for air-conditioning in a housing as shown in FIG. 14. The compressor with a built-in electric motor is housed in a container 152 made of iron, together with a compression mechanism 150 and an electric motor 151. In the hybrid vehicle, furthermore, the arrangement of devices in an engine room is based on that of the conventional motor vehicle. Thus, there is no space or location for installing the conventional compressor with the built-in electric motor for air-conditioning in the housing within the engine room.
What is worse, the conventional compressor with the built-in electric motor has large axial dimensions. That is, a discharge port 154, a suction port 155, inner and outer electric connection parts 156, and a mounting leg portion 157 are longitudinally extended from both ends of the container 152. Such a complicated construction of the compressor is hardly incorporated in an electric-powered vehicle which has been only realized in a small-sized vehicle.
Simultaneously, the conventional compressor with the built-in electric motor is made of iron and is large, so that the total weight thereof is about 9 kg or more. Thus, it becomes a problem in realizing the high speed and the energy saving because of the increase in driving load when it is mounted on the full-sized mobile structure.
It becomes urgent business to provide a small-sized and lightweight compressor with a built-in electric motor now in a tendency of planning an electric operation of various kinds of load by using a working voltage of 42 volts in a gasoline-powered vehicle, a hybrid vehicle, or an electric-powered vehicle. For this reason, it is considered to use a small and lightweight compressor with a built-in electric motor having a container made of aluminum.
When a terminal 156 is provided on the container 152 made of iron, a weld joint 167 is used. As the weld joint 167, an installation flange 165, which is made of iron, for the terminal 156 is welded to a connection opening 166 of the container 152. On the other hand, when a compressor with a built-in electric motor has an aluminum container 158, the iron installation flange 165 cannot be welded. To solve this problem, as shown in FIG. 15, an installation flange 168 of a terminal 164 is welded to an installation plate 169 made of iron in advance, and the installation plate 169 is placed at a connection opening 171 of the container 158, and is screwed by a plurality of bolts 170. A sealing member 172 is placed between the installation plate 169 and the connection opening 171.
With this structure, the iron installation plate 169 is made relatively thick and heavy to withstand the refrigerant gas pressure. In addition, the installation plate 169 has a flange 173 for the installation using the bolts 170, and becomes large. The multiple bolts 170 for the screwing are also made of iron. Consequently, a part for installing the terminal 164 becomes even heavier than the case of the conventional compressor.
To address this problem, the installation flange 168 of the terminal 164 may be made of aluminum as the container 158 is. However, there are problems in terms of technique, time, and cost such as developing a glass seal material suitable for the aluminum installation flange.
If the conventional terminal 156 having the iron installation flange 165 can be installed on an aluminum container, this problem is adequately solved.